Computer-implemented keyboard power management system

ABSTRACT

A method for displaying power sustainability data for a battery includes providing a processor and a memory device coupled to the processor and receiving power sustainability data at a plurality of times. The power sustainability data includes a remaining battery capacity and a light exposure level. The method also includes storing the plurality of times and data values associated with the power sustainability data in the memory device. Additionally, the method includes obtaining most recently received data values for remaining battery capacity and light exposure level and displaying the most recently received data values for remaining battery capacity and light exposure levels.

CROSS-REFERENCES TO RELATED APPLICATIONS

The following regular U.S. patent applications (including this one) arebeing filed concurrently, and the entire disclosure of the otherapplication is incorporated by reference into this application for allpurposes:

-   -   application Ser. No. 13/284,318 filed on Oct. 28, 2011,        entitled, “System and Method for Solar Keyboard Power        Management”; and    -   application Ser. No. 13/284,329 filed on Oct. 28, 2011,        entitled, “Computer-implemented Keyboard Power Management        System”.

BACKGROUND OF THE INVENTION

Solar-powered electronic devices are currently available for purchaseand use. An example of such a device is a solar-powered calculator. Somesolar-powered calculators do not have a battery for providing analternate source of power in the absence of light. As a result, if thelight is not sufficient, these solar-powered calculators may not work.

Despite the progress made in solar-powered electronic devices, there isa need in the art for improved methods and systems related to thesesolar-powered electronic devices.

SUMMARY OF THE INVENTION

The present invention relates generally to power management for a solarpowered device. More particularly, the present invention relates toproviding power consumption and re-charging information for asolar-powered device. Merely by way of example, a wireless solar-poweredkeyboard utilizing one or more solar panels is provided. In anembodiment, the keyboard communicates with a computer over a wirelessconnection and utilizes the one or more solar panels as an energysource.

According to an embodiment of the present invention, a method ofdetermining a power sustainability status of a device having one or moresolar panels and a battery is provided. The method includes receiving arequest to indicate the power sustainability status, measuring a voltageof the battery, determining a usage level of the device and a low powersustainability threshold, and computing a remaining capacity of thebattery using the voltage of the battery and usage level of the device.The method also includes computing a light exposure level associatedwith the one or more solar panels, determining a power sustainabilityindex using at least one of the remaining capacity of the battery or thelight exposure level, and comparing the power sustainability index tothe low power sustainability threshold.

According to another embodiment of the present invention, a method ofindicating a power sustainability status of a device having a processor,a timer, one or more solar panels, and a battery, is provided. Themethod includes generating, using the timer, a trigger at a particulartime interval. In response to at least the trigger, the method alsoincludes measuring a voltage of the battery, computing, in theprocessor, a remaining capacity of the battery using the voltage of thebattery, and computing, in the processor, a light exposure levelassociated with the one or more solar panels. The method also includesdetermining a power sustainability index using at least one of theremaining capacity of the battery or the light exposure level,determining the power sustainability status based on the powersustainability index, and providing an indication of low powersustainability status.

According to another embodiment of the present invention, a solarkeyboard is provided that includes a housing, a keystroke input moduledisposed in the housing and operable to provide character data to aprocessor device, and a battery disposed in the housing. The solarkeyboard also includes one or more solar panels disposed on the housing,a power sustainability computation module, a power status input device,and a power status indicator unit.

According to another embodiment of the present invention, a method fordisplaying power sustainability data for a battery is provided. Themethod includes providing a processor and a memory device coupled to theprocessor, receiving power sustainability data at a plurality of times,the power sustainability data comprising a remaining battery capacityand a light exposure level. The method further includes storing datavalues in the memory device, the data values associated with the powersustainability data and the plurality of times. Additionally, the methodincludes obtaining most recently received data values for remainingbattery capacity and light exposure level and displaying the mostrecently received data values for remaining battery capacity and lightexposure levels.

According to another embodiment of the present invention, anon-transitory computer-readable storage medium is provided thatincludes instructions to provide a message on a display device. Theinstructions include instructions that cause the data processor toreceive power sustainability data at a plurality of times, the powersustainability data comprising a remaining battery capacity and a lightexposure level. In addition, instructions are included that cause thedata processor to store data values in the memory device, the datavalues associated with the power sustainability data and the pluralityof times and instructions that cause the data processor to display themost recently received data values for remaining battery capacity andlight exposure levels.

According to another embodiment of the present invention, a solarkeyboard power management system is provided that includes a solarkeyboard operable to provide character data to a processor device. Thesolar keyboard includes a keystroke input module, a battery, and one ormore solar panels electrically coupled to the battery. In addition, thesolar keyboard power management system includes a graphical userinterface operable to provide power sustainability data on a displaydevice. The graphical user interface includes a light level indicatorpane, a battery information pane, and a status message pane.

According to an embodiment of the present invention, a solar keyboardpower management system is provided that includes the ability to provideinformation to the keyboard user regarding the power sustainabilitystatus of the keyboard A minimal amount of power is required todetermine and provide the status. The power sustainability status isbased on the remaining capacity of the battery and the light exposurelevel to the solar panels. Periodically, and additionally upon request,a keyboard processor determines the remaining capacity of the batteryand the light exposure level to the solar panels. Based on this data,the keyboard processor determines the power sustainability status of thekeyboard. When the status is determined upon request, the status isprovided by flashing an LED associated with the resulting status. Whenthe status is determined periodically, only a status that warrantswarning the user is provided.

According to another embodiment of the present invention, a solarkeyboard power management system is provided that includes the abilityto provide information to the keyboard user regarding the powersustainability status of the keyboard. Along with the character datathat the keyboard provides to a computer, the keyboard may also sendkeyboard power-related data. A power management application running onthe computer may timestamp and store the power-related data for laterretrieval. The application may use the computer display to present auser interface that includes current keyboard power status information,historical trends of battery capacity and light exposure, and a messagedescribing the current power status and advice. Having the computeranalyze and display the data allows for presenting more useful anddetailed information than the keyboard itself could provide, and theapplication may be powered by the computer's power source withoutfurther draining the keyboard power that is being monitored.

According to an embodiment of the present invention, a solar computerkeyboard powered by solar energy is provided. The solar computerkeyboard includes a battery for storing energy and is operable tooperate indoors and/or in dark or dim conditions for some period oftime. As described throughout the present specification, monitoring ofthe battery capacity and the light exposure is provided as part of apower management capability for the solar computer keyboard. Suchmonitoring may include determining when the energy levels should bemeasured, and when and how to notify the user that the energy levels aretoo low. Embodiments of the present invention reduce or minimize theenergy used for measuring, determining, and notifying a user incomparison with conventional techniques.

Numerous benefits are achieved by way of the present invention overconventional techniques. For example, embodiments of the presentinvention provide very low power techniques to monitor and provideproactive feedback to the user regarding power levels of the keyboard toavoid the keyboard becoming inoperable due to a drained battery.Additionally, embodiments provide a dedicated “CheckLight” button on thekeyboard that provides a positive or negative indication related to thekeyboard energy balance between incoming light and battery remainingcapacity. As described below, pressing the CheckLight button may triggera power management application running on the computer to displaycurrent remaining battery capacity and light exposure levels as well ashistorical trends for remaining battery capacity and light exposurelevels. These and other embodiments of the invention, along with many ofits advantages and features, are described in more detail in conjunctionwith the text below and attached figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified schematic diagram illustrating components of asolar keyboard power management system according to an embodiment of thepresent invention;

FIG. 2 is a graph of remaining battery capacity as a function of batteryvoltage according to an embodiment of the present invention;

FIG. 3 is a simplified flowchart illustrating a method of determining apower sustainability status according to an embodiment of the presentinvention;

FIG. 4 is a simplified flowchart illustrating a method of monitoringpower sustainability of a device according to an embodiment of thepresent invention;

FIG. 5 is a simplified flowchart illustrating a method of receiving andstoring power sustainability data according to an embodiment of thepresent invention;

FIG. 6 is a simplified flowchart illustrating a method of displayinginformation regarding the power sustainability of a device according toan embodiment of the present invention;

FIG. 7 and FIG. 8 are exemplary screen shots displayed by the powermanagement application according to an embodiment of the presentinvention;

FIG. 9 is a simplified diagram of a solar keyboard according to anembodiment of the present invention; and

FIG. 10 is a simplified state diagram illustrating operation of thesolar keyboard according to an embodiment of the present invention.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Embodiments of the present invention relate to power management methodsand systems for a solar powered device. More particularly, the presentinvention relates to providing power consumption and re-charginginformation for a solar-powered device. Merely by way of example, awireless solar-powered keyboard utilizing one or more solar panels isprovided. In an embodiment, the keyboard communicates with a computerover a wireless connection and utilizes the solar panels as an energysource.

As described more fully throughout the present specification, accordingto an embodiment of the present invention, the solar keyboard managementsystem monitors the remaining battery capacity, determines whethercurrent use of the keyboard is sustainable considering the amount oflight to which the solar panels are exposed, and provides an indicationof the power sustainability status to a user so that if power is notsustainable for current use, the keyboard may be placed or orienteddifferently to provide sufficient light. Power sustainability status mayindicate the extent to which continued use of the keyboard under presentlight conditions may be sustained over time.

FIG. 1 is a simplified schematic diagram illustrating components of asolar keyboard power management system according to an embodiment of thepresent invention. Electronic keyboard 100 connects to processor 180over communications link 175, and processor 180 is connected to adisplay 190 over communications link 185. Communications link 175 may bea wireless network connection. The wireless connection may be Bluetoothor any other standard or proprietary wireless network protocol.Communications link 185 may be a wired connection and may be a networkor a direct connection between processor 180 and display 190.

The electronic keyboard includes a housing 900 (see FIG. 9) includingkeystroke input module 105, which includes a plurality of keystrokeinput elements or devices and is operable to receive input in responseto an alphanumeric key, or other suitable input element or device suchas a media control button, being pressed on the keyboard. The keystrokeinput module 105 generates character data associated with the pressedkey and sends the character data to processor 180 over communicationlink 175. Receipt of the character data by processor 180 may affect thecontent that the processor 180 sends to display 190 over communicationlink 185.

Solar panels 130 are coupled to the housing, for example, disposed on anupper surface of the housing and convert light energy into electricalenergy for powering electronic keyboard 100 and recharging battery 110.In one embodiment, all the power from the solar panels 130 goes tocharging battery 110, and battery 110 is used to power the keyboard. Inan alternate embodiment, solar panels 130 provide power directly to thekeyboard 100 when the keyboard is in use, and any surplus power is usedto recharge battery 110. Thus, depending on the embodiment, the lightlevels may be measured, the current available from the solar panels maybe computed, the energy used by the keyboard may be computed, and thevarious values can be displayed to provide a real time or averagedsummary of the power available from the solar panels and the battery aswell as the power consumption by the keyboard. These values may be basedon real-time data or based on data collected over one or morepredetermined periods (e.g., minutes, hours, days, week, months, years,or the like).

In an embodiment, the solar keyboard is only charged through the solarpanels, lacking any other source of charging the battery or providingpower to the keyboard. For example, the keyboard may lack an electricaladapter for receiving power from a wall socket, a USB power source, orother AC or DC power source. In an alternative embodiment, the solarkeyboard can utilize other energy sources in addition to the solarpanels, for example, a USB cable, a DC power source, or the like and/ormay receive electrical power from a plurality of sources.

Power switch 160 is an on/off switch. In one embodiment, while thekeyboard is turned off, no energy is being consumed from the battery;however, the solar panels are operable to recharge the battery. In analternate embodiment, while the keyboard is turned off, the keyboard isnot operable as a keystroke input device; however, power monitoring andmanagement functions may consume energy from the battery. In anembodiment, when the switch is moved from the “off” position to the “on”position, the keyboard checks the battery capacity and flashes a red LEDif the current remaining battery capacity is below a low powersustainability threshold and flashes a green LED if the current batterylevel is sufficient. In an embodiment, the low power sustainabilitythreshold may be 40% of remaining battery capacity. As described morefully below, this red LED and this green LED can be components of powerstatus indicator unit 120, discussed in additional detail below.

Power sustainability computation module 140 monitors the power systemand determines power sustainability for the keyboard. Once triggered,power sustainability computation module 140 measures the voltage ofbattery 110, and determines an amount of remaining battery capacity. Amicrocontroller may be included in power sustainability computationmodule 140 to monitor battery voltage and compute remaining capacity.For example, FIG. 2 is a graph of remaining battery capacity as afunction of battery voltage according to an embodiment of the presentinvention. The graph illustrates a function that converts measuredbattery voltage to remaining battery capacity based on the typicaldischarge curve for the particular type of battery used in the keyboard(different battery types may have different discharge curves). In anembodiment, the amount of remaining battery capacity may be determinedin milliampere-hours (mAh) and mapped to a percentage of the totalbattery capacity. For example, according to FIG. 2, a battery with ameasured voltage of 2.8V has approximately 96% of capacity remaining; abattery measured voltage of 2.6V has approximately 82% capacityremaining, and a battery with a measured voltage of 2.4V hasapproximately 25% capacity remaining. To allow displaying the maximumand minimum values of 100% and 0%, the scale is shrunk so that 2.8V willdisplay 100% and 2.4V will display 0%. The slope of the curve in theexample is very steep; that is, a very small change in the measuredvoltage may result in a very different value for remaining batterycapacity. For at least that reason, embodiments of the present inventionprovide methods and a system to provide accurate voltage measurement,and/or to average several independent voltage measurements and use theaverage voltage as input to the remaining battery capacity function.Alternatively, each independent voltage measurement may be input intothe remaining battery capacity function, and the plurality of remainingbattery capacity outputs may be averaged together, and the averagebattery capacity may be used to determine power sustainability.

The power sustainability computation module 140 may also determine theamount of light being received by the solar panels. In an embodiment,the power sustainability computation module 140 may measure the currentgenerated by the solar panels as an indication of the amount of lightbeing received. Based on the remaining battery capacity and the amountof light being received by the solar panels, power sustainabilitycomputation module 140 may determine power sustainability. Low powersustainability may indicate the need to expose electronic keyboard 100to more light. Power sustainability may also be determined using anexpected average use of the keyboard. In an embodiment, a constantrepresenting the average number of keystrokes per year may be used asinput to determine the power sustainability. In an alternate embodiment,the inclusion of a real-time clock may allow for dynamic usagestatistics for the keyboard to be collected and used as input into thepower sustainability index.

Preferably, the battery is operated near 100% capacity to providereliable long term operation. Cycling of the battery is allowed, evenover a long term (e.g., a year), to provide for reliable operation inhigh latitude environments in which the battery can slowly charge overthe summer in the northern latitudes and slowly discharge over thewinter. Table 1 is a chart showing remaining battery capacity andminimum light exposure levels needed to sustain power, according to anembodiment of the invention. The numbers in the table have been derivedassuming a constant expected usage, although other usage levels otherthan constant usage can be utilized according to embodiments of thepresent invention. As described below, the usage level can be dynamic,measured over a predetermined time period, or the like. One of ordinaryskill in the art would recognize many variations, modifications, andalternatives.

The greater the remaining battery capacity, the lower the required lightexposure level needed to sustain power. For example, when the remainingbattery capacity is between 90%-100%, power to the keyboard may besustained with a minimum light exposure level of 50 lux. When theremaining battery capacity is between 60%-90%, power to the keyboard maybe sustained with a minimum light exposure level of 100 lux. When theremaining battery capacity is between 30%-60%, power to the keyboard maybe sustained with a minimum light exposure level of 150 lux. When theremaining battery capacity is between 0% and 30%, the minimum lightexposure level is 200 lux to sustain power. When the remaining batterycapacity is 0%, the keyboard may stop functioning unless and until alight exposure level of 300 lux is provided to the solar panels. Aremaining battery capacity of 0% may not mean that there is no chargeleft in the battery, since at 0% capacity there may still be a reserveof battery capacity remaining (e.g., 10% of the battery capacity),enabling operation even at low battery capacities. Other reserve valuescan be utilized and a 10% reserve value is merely provided by way ofexample.

TABLE 1 Minimum light exposure level based on remaining battery capacityRemaining battery Minimum light capacity exposure level to (% of batterysustain power capacity) (lux)  90-100  50 60-90 100 30-60 150 >0-30  2000 300

In an embodiment, power sustainability may be determined by performingseveral steps. First, the remaining battery capacity may be used todetermine the required light exposure level. In an embodiment, theexpected usage may be a constant that is used in constructing a tablesuch as Table 1 that provides an association between remaining batterycapacity and required light exposure level for sustainability.Alternatively, a required light exposure level function may takeremaining battery capacity and dynamically-determined expected usage asinputs and output the required light exposure level. Regardless of howthe required light exposure level may be determined, the next step is tocompare the present light exposure level to the required light exposurelevel. If the present light exposure level is greater than or equal tothe required light exposure level, then the power sustainability may besufficient. If the present light exposure level is less than therequired light exposure level, then the power sustainability may be low.If the remaining battery capacity is 0% and the light exposure level isless than 300 lux, then the power sustainability status may becritically low.

Although Table 1 illustrates the minimum light exposure level needed tosustain current use, which is determined based on remaining batterycapacity, other minimum light exposure levels can be associated with theremaining battery capacity. Thus, the numbers and ranges provided inTable 1 are not absolute, but are provided as exemplary numbers andranges for the illustrated embodiment. Different hardware (e.g., solarcells and batteries) with different features will utilize differentamounts of power depending on the particular implementation.Additionally, different ranges of remaining battery capacity can beassociated with different light exposure levels and differentcurrent/voltage characteristics of the solar panels. Thus, embodimentsof the present invention provide a dynamic system in which the differentdesired solar power levels are utilized based on different levels ofbattery charge.

In another embodiment of the invention, a power sustainability functionmay take the remaining battery capacity and light exposure level asinputs and output a power sustainability index. If the expected usage isa constant, the power sustainability function may be derived based onthe expected usage constant. Alternatively, the expected usage may be aninput to the function, and the expected usage may be a constant or maybe determined dynamically for the particular keyboard based on past use.The expected usage may be determined by logging the number of keystrokesper unit time, and averaging these values over a longer period of time.For example, the number of keystrokes per minute may be logged, and arunning average of keystrokes per minute may be computed over any timeperiod such as an hour, day, week, month, or year. The powersustainability index that is output by the power sustainability functionmay be compared with a low power sustainability threshold. If the indexis greater than the low power sustainability threshold, then the currentusage is determined to be sustainable under the current lightingconditions (sufficient power sustainability). If the powersustainability index is less than or equal to the low powersustainability threshold, then the current usage is determined not to besustainable under the current lighting conditions (low powersustainability). In addition, the power sustainability index may becompared to a critical low threshold, and if the index is less than orequal to the critical low threshold, the keyboard may soon be disabled(critically low sustainability).

Power sustainability computation module 140 may be triggered intooperation in a variety of ways. In an embodiment, transitioning powerswitch 160 from an “off” position to an “on” position may cause powersustainability computation module 140 to determine a powersustainability status based on the present remaining battery capacityand indicate the status through power status indicator unit 120. Powerswitch 160 may be any kind of power switch with an on and off positionthat is known in the art, such as a slider, a toggle button, or thelike.

In another embodiment, power sustainability computation module 140 maybe triggered by power status input device 150. Power status input deviceis a device or element that a user can activate when the keyboard isalready in use to obtain an updated power sustainability status. In anembodiment, power status input device 150 may be a “Check Light” buttonon electronic keyboard 100, which when pressed, causes powersustainability computation module 140 to determine power sustainability.

FIG. 9 is a simplified diagram of a solar keyboard according to anembodiment of the present invention. The solar keyboard includes ahousing 900, a keystroke input module 910 disposed in the housing andoperable to provide character data to a processor device, and a battery920 disposed in the housing. The solar keyboard further includes one ormore solar panels 930 disposed on the housing, and a powersustainability computation module 940. The solar keyboard also includesa power status input device 950 and a power status indicator unit 960.The dashed lines corresponding to battery 920 and power sustainabilitycomputation module 940 indicate that these components are inside thekeyboard, and may not be visible from the outside.

FIG. 3 is a simplified flowchart illustrating a method of determining apower sustainability status according to an embodiment of the presentinvention. The method includes receiving a request for powersustainability status (310), for example, in response to pressing aCheck Light button on the keyboard. The method also includes measuringthe battery voltage (312) and determining a usage level and a low powersustainability threshold (314). The usage level may be an expected usagelevel based on historical data for a particular user, a constant valuestored in a memory, a value dependent on a recent time period, or thelike.

The method further includes computing a remaining capacity of thebattery (316) using the voltage of the battery and usage level of thedevice and computing a light exposure level associated with the one ormore solar panels (318). In addition, the method includes determining apower sustainability index (320) using at least one of the remainingcapacity of the battery or the light exposure level and comparing thepower sustainability index to the low power sustainability threshold(322), and providing an optional indication of the power sustainabilitystatus of the device. As examples, if the power sustainability index isgreater than or equal to a low power sustainability threshold, then anindication of sufficient power sustainability is provided (326), meaningthat the current light exposure is sufficient for powering the keyboardat the expected usage with the remaining battery capacity. The low powersustainability threshold is an index value below which the keyboardcannot sustain power at the current light exposure levels. If the powersustainability index is less than the low power sustainabilitythreshold, then an indication of low power sustainability is provided(324), meaning that more light exposure will be necessary to sustain theexpected usage of the keyboard with the current remaining batterycapacity. As will be evident to one of skill in the art, the sufficiencyof battery capacity and light exposure levels will depend on thekeyboard use, which may vary as a function of time. Since powerconsumption varies depending on usage, the indication is a snapshot intime based on the available data including current and/or historicalusage and current and/or historical light intensity.

It should be appreciated that the specific steps illustrated in FIG. 3provide a particular method of providing an indication of powersustainability status according to an embodiment of the presentinvention. Other sequences of steps may also be performed according toalternative embodiments. For example, alternative embodiments of thepresent invention may perform the steps outlined above in a differentorder. Moreover, the individual steps illustrated in FIG. 3 may includemultiple sub-steps that may be performed in various sequences asappropriate to the individual step. Furthermore, additional steps may beadded or removed depending on the particular applications. One ofordinary skill in the art would recognize many variations,modifications, and alternatives.

In yet another embodiment, power sustainability computation module 140may be triggered by timer 170. Timer 170 may be configured to triggerpower sustainability computation module 140 at a periodic time interval,for example, every 90 seconds. The keyboard power system may bemonitored continuously while the keyboard is in use, even when the userdoes not explicitly request a status report.

FIG. 4 is a simplified flowchart illustrating a method of indicating apower sustainability status of a device having a processor, a timer, oneor more solar panels, and a battery according to an embodiment of thepresent invention. The method includes generating, using the timer, atrigger at a particular time interval (410). The timer may be generatedperiodically after a certain time interval such as every two minutes, atpre-determined times such as on the quarter hour, at random timesselecting within a range of time intervals, or the like. The methodfurther includes, in response to at least the trigger measuring avoltage of the battery (412), computing, in the processor, a remainingcapacity of the battery (414) using the voltage of the battery, andcomputing, in the processor, a light exposure level associated with theone or more solar panels (416). Also, the method includes determining apower sustainability index (418) using at least one of the remainingcapacity of the battery or the light exposure level, optionallydetermining that the power sustainability index is less than or equal to(i.e., below or at) a first low power sustainability threshold (420),and providing an indication that a power sustainability status of thedevice is in a low power sustainability state (422). The first low powersustainability threshold is an index value below which a warning may beissued that current usage cannot be sustained. If the index is greaterthan the first low power sustainability threshold, then the user may notbe interrupted with an unrequested status report.

It should be appreciated that the specific steps illustrated in FIG. 4provide a particular method of indicating a power sustainability statusof a device having a processor, a timer, one or more solar panels, and abattery according to an embodiment of the present invention. Othersequences of steps may also be performed according to alternativeembodiments. For example, alternative embodiments of the presentinvention may perform the steps outlined above in a different order.Moreover, the individual steps illustrated in FIG. 4 may includemultiple sub-steps that may be performed in various sequences asappropriate to the individual step. Furthermore, additional steps may beadded or removed depending on the particular applications. One ofordinary skill in the art would recognize many variations,modifications, and alternatives.

There may be a number of ways that power status information may bepresented to the user. In an embodiment, status may be presented throughpower status indicator unit 120 on the keyboard that may comprise aplurality of LEDs. Each LED may correspond to a distinct powersustainability status, and the power status indicator unit 120 mayilluminate the LED that corresponds to the present status of electronickeyboard 100. Illuminating the LED may comprise flashing the LED orturning on and sustaining the illumination for some time period. Forexample, power status indicator unit 120 may comprise two LEDs: one LEDcorresponding to a sufficient power sustainability status and the otherLED corresponding to low power sustainability status. The plurality ofLEDs may each be labeled to indicate the status represented by the LED.In an embodiment, distinct LED colors are used to distinguish the powersustainability status represented by the LED. For example, a green LEDmay be used to indicate sufficient power sustainability status and a redLED may be used to indicate low power sustainability status. An LEDrepresenting sufficient power sustainability status may be labeled witha positive indication such as a smiley face icon, a thumbs up icon, or aword synonymous with “good” or “sufficient”. Likewise, an LEDrepresenting low power sustainability status may be labeled with anegative indication such as a frowning face icon, a thumbs down icon, ora word synonymous with “bad” or “insufficient.” In an alternateembodiment, power status indicator unit 120 may be a display provided onkeyboard 100, and power sustainability status presented through thekeyboard display.

Each way of triggering power sustainability computation module 140 maybe associated with one or more ways of providing status information tothe user. For example, transitioning a power switch from an off to an onposition may flash an LED on the keyboard to indicate present remainingbattery capacity status (without using the light exposure level).Another example is that when a user presses a button on the keyboard, anLED on the keyboard may flash to indicate overall power sustainabilitystatus, which considers both remaining battery capacity and the lightexposure level.

In addition, in an embodiment, monitoring power sustainability status inresponse to a trigger from timer 170 may only present status to warn theuser of a low sustainability status. For example, the LED correspondingto a low sustainability status may flash repeatedly. In an embodiment,an LED may flash ten times. There may be no user presentation when thestatus is sufficient in order to minimize user distraction when nochange to the available light is needed, increasing the probability thatthe user will notice when there is a low power sustainability status. Inan embodiment, when power sustainability computation module 140determines that the power sustainability status is critically low, thekeyboard may respond in one or more ways including, for example, theperformance of the keyboard may degrade (longer delay between hitting akey and the appearance of character data on the computer display), thekeyboard may stop sending character data to the computer, the LEDassociated with low sustainability may flash each time the user pressesa key, may be illuminated continuously, or may flash at a certainfrequency. In an embodiment, the frequency of flashing the LED may varydepending on the battery voltage.

A power management application (may be referred to herein as “theapplication”) may run on the computer (e.g., processor 180) to which thekeyboard sends character data. In an embodiment, power sustainabilitystatus may be presented on display 185. A power management applicationrunning on processor 180 may receive power status information from thekeyboard and provide the user with current status, historical trendinformation, and feedback on the lighting conditions and recommendationsfor repositioning the keyboard if necessary.

Whenever power sustainability computation module 140 generates a new setof power sustainability data, the data may be sent from the keyboard toprocessor 180 and received by the application. The keyboard maydetermine when to send data and when not to send data to the processor.Sending the data requires power, so sending data too often may depletethe very power that is being measured. In addition, sending data whenthe keyboard is idle may waste power as the user might not be present toview the status. Also, since the battery voltage measurements may benoisy, several battery voltage measurements may be averaged together,and a single aggregate remaining battery capacity sent to processor 180less frequently than at each and every battery voltage measurement.Thus, power sustainability averages may be sent to the application whenthe keyboard is in active use. In an embodiment, power sustainabilitydata may be sent within a particular time interval after character datais delivered to the processor. For example, power sustainability datamay only be sent to the processor within two minutes of character datasent to the processor. In an embodiment, after two minutes ofinactivity, the keyboard may become completely idle, and may no longerproactively monitor the power sustainability status until the nextkeystroke.

The data received from the keyboard may be any combination of batteryvoltage, a remaining battery capacity, a light intensity level, a powersustainability index, and/or averages thereof. The battery capacity andlight intensity level may be expressed in any way known to persons ofordinary skill in the art. For example, remaining battery capacity maybe expressed as a percentage of the full battery, and the lightintensity level may be expressed as a lux value. The powersustainability index may be a number within a particular range ofnumbers. For example, within a range of 0 representing completely nopower and 100 representing completely full power, a power sustainabilityindex of 90 may indicate excellent sustainability.

FIG. 5 and FIG. 6 are simplified flowcharts illustrating a method fordisplaying power sustainability data for a battery according to anembodiment of the present invention. Referring to FIG. 5, the methodincludes providing a processor and a memory device coupled to theprocessor and receiving power sustainability data at a plurality oftimes (510), the power sustainability data comprising a remainingbattery capacity and a light exposure level. In an embodiment, thecomputer (such as processor 180) receives from the keyboard, dataregarding the power sustainability status of the keyboard. The methodfurther includes storing data values in the memory device, the datavalues associated with the power sustainability data and the pluralityof times (512). For example, a power management application running onthe computer accepts the power sustainability data as input, and maystore each data point in the input with a timestamp corresponding to thetime the data was received by the processor for later retrieval andanalysis. Alternatively, the timestamp may be generated by the keyboardand received by the processor together with the power sustainabilitydata. The data may be stored in any kind of volatile or non-volatilememory/storage device. Additionally, the method includes displaying themost recently received data values for remaining battery capacity andlight exposure levels (514)

Referring to FIG. 6, the method includes optional steps of receiving arequest to provide power sustainability information (612). The methodfurther includes optional steps for determining, using the processor, anenergy reserve level of the remaining battery capacity characterized asat least one of high, good, fair, low, very low, or depleted (614) anddetermining, using the processor, a trend of the remaining batterycapacity characterized as at least one of increasing, decreasing, orunchanging (616). Also, the method includes an optional step forgenerating a message using the energy reserve status of the remainingbattery capacity and the trend of the remaining battery capacity andproviding the message on a display device (618).

It should be appreciated that the specific steps illustrated in FIG. 5and FIG. 6 provide a particular method for displaying powersustainability data for a battery according to an embodiment of thepresent invention. Other sequences of steps may also be performedaccording to alternative embodiments. For example, alternativeembodiments of the present invention may perform the steps outlinedabove in a different order. Moreover, the individual steps illustratedin FIG. 5 and FIG. 6 may include multiple sub-steps that may beperformed in various sequences as appropriate to the individual step.Furthermore, additional steps may be added or removed depending on theparticular applications. One of ordinary skill in the art wouldrecognize many variations, modifications, and alternatives.

As explained above, the application may receive data from the keyboardperiodically and store the data for later use. However, in someembodiments, the data is only displayed upon certain events. In anembodiment, the incoming data may be analyzed by the power managementapplication upon receipt, and the application may display a warning ifthe remaining battery capacity is determined to be critically low. Thus,embodiments can present power status information via the display.

In addition to requesting a power status indication from the keyboarditself, pressing the keyboard Check Light button may additionally causeprocessor 180 to launch the power management application to displaypower status information on display 185.

In another embodiment, the application may be launched to display statusthrough a user interface provided by processor 180. The application mayprovide a single status snapshot or may provide a dynamic status windowthat is updated as new data is received.

In an embodiment, when the keyboard disables sending character data tothe computer because of critically low power sustainability, thekeyboard may send an indication to the computer that the keyboard isdisabled. In response to receiving such an indication, the computer maylaunch the power management application to warn the user of the lowpower status and to provide instructions regarding necessary action topreserve sustainability of the power.

In an embodiment, each time the application receives a set of powersustainability data, the received data may be stored with a timestampand used to determine a historical trend over a time period. The timeperiod may be any practical time period such as minutes, hours, day,weeks, or months. The historical trend time period may be selected asdescribed below. In another embodiment, multiple data sets may bereceived within a certain time period and averaged together, and theaverage data values may be stored with a timestamp. For example, thepower management application may receive data every 90 seconds from thekeyboard, but the application may average together the data receivedover a ten minute interval, and one set of data may be stored for eachten minute interval that is comprised of the average of the datareceived during the interval. In an alternate embodiment, a runningaverage of remaining battery capacity values received during the lastday, week, or month window may be stored.

Upon receiving a request to display status information to the user, thepower management application may retrieve and display the data stored inmemory. The most recent data may be displayed to represent the presentstatus. For example, current remaining battery capacity may be displayedand/or current light exposure levels may be displayed. In addition oralternatively, a trend may be plotted and displayed as a graph ofhistorical data over time. The historical remaining battery capacityvalues over time may be displayed as a graph for a selected historicaltime interval, and similarly, light exposure levels may be plotted anddisplayed as a graph over a selected historical time interval. Thehistorical trends may alternatively be represented and displayed as achart, textual data, or any other way of displaying a historical trend.

FIG. 7 and FIG. 8 are exemplary screen shots displayed by the powermanagement application according to an embodiment of the presentinvention. A graphical user interface 700 is provided as illustrated inFIG. 7. The graphical user interface (GIU) includes a plurality ofsections useful to display information to a user of the solar keyboard.The GUI includes a first section, which can be referred to as a lightlevel indicator pane 701. In the illustrated embodiment, the light levelindicator pane 701 is marked by an icon of the sun in the top leftcorner of this section. The GUI also includes a battery information pane702, which can be used to indicate the remaining battery capacity aswell as the history of the remaining battery capacity as a function oftime. In FIG. 7, the battery information pane 702, which is marked by alightning bolt in the top left corner, is used to indicate the historyof the remaining battery capacity. In FIG. 8, the battery informationpane 702 is used to indicate the remaining battery capacity at a giventime. The GUI further includes a status message pane 703 that is usefulin communicating messages to the user. Multiple messages can bedisplayed in the status message section at a given time.

In the embodiment illustrated in FIG. 7, the light level indicator pane701 includes a dial 710 that displays the present light intensity levelbeing received by the solar panels. The most recently received lightintensity value is shown. Although a generally circular dial isillustrated in FIG. 7, this particular numerical range indicator is notrequired by embodiments of the present invention, and other rangeindicators, including linear or logarithmic scales, can be utilizedaccording to an embodiment of the present invention. Inside dial 710 isa digital (numeric) representation of the light intensity levelexpressed in lux (715). In implementations utilizing linear scales, thedigital representation can be placed below, above, or adjacent to thelinear scale as appropriate to the particular application. One ofordinary skill in the art would recognize many variations,modifications, and alternatives.

The GUI also includes a pane operable to provide information related tothe remaining battery capacity. When trend chart indicator 750 ishighlighted, trend chart 720 shows the historical trend of remainingbattery capacity data over a number of months. For example, when 12M ishighlighted in trend chart 720, the trend data may be shown for the pastyear. When 3M is highlighted, data may be shown over the last quarter,and when 1M is highlighted, only data collected over the past month maybe displayed in the trend chart. In other embodiments, other timeperiods such as days, weeks, multiple weeks, or other suitable timeperiods can be utilized, and the examples provided herein are merelyexemplary. Alternatively, as shown in FIG. 8, when the present remainingbattery capacity indicator 830 is highlighted, then the currentremaining battery capacity is displayed. In the example shown in FIG. 8,the remaining battery capacity is 100%.

Status message 730 provides a summary status to the user indicating thecurrent power sustainability level and providing recommended changes ifthe status is not favorable. The summary status message may bedetermined using trend information, such as whether remaining batterycapacity or light exposure level is increasing, decreasing, or stayingthe same. The status message 730 may include words, symbols, graphics,and the like. In the example shown in FIG. 7, status message 730 informsthe user that the current power status is excellent and the energyreserve is high. The “What does it mean?” link 740 is a link to moredetailed information and recommendations. For example, clicking on the“What does it mean?” link may display the following message:

-   -   “You've got plenty of juice right now. Your current reserve lets        you use your keyboard in total darkness for four months—so you        can type all you want. Want to keep your energy reserve high?        Expose your keyboard to enough sunlight or indoor light even        when you're not using it. (Don't worry—it recharges with light        when it's switched off.) Your best bet is to keep your keyboard        no more than 9 feet (3 meters) from a window with direct line of        sight.”

In an embodiment, the present remaining battery capacity is compared toa set of thresholds defining ranges of battery status. Table 2 shows thethresholds for the ranges and the corresponding status.

TABLE 2 Power State Ranges Maximum Energy Minimum threshold Reservethreshold (%) (%) Status 90 100 High 80  90 Good 30  80 Fair 10  30Low >0  10 Very Low  0   0 Depleted

As described herein, the power management application displays aplurality of status messages including “Need more light” and“Excellent.” Additionally, when the remaining battery capacity is in apredetermined range (e.g., less than 30%), an indication can be providedto the user, for example blinking the red LED, and/or a message can bedisplayed, for example, “Warning! Your keyboard might stop workingsoon.” In some implementations in which the computed remaining batterycapacity reaches zero, some or all of the functionality of the keyboardmay be disabled until sufficient light is provided (e.g., >300 lux). Insome embodiments, if there is enough light to continue working and thekeyboard is still being utilized (i.e., the keyboard is not in an idlestate), the energy budget trend is still negative and more light will beneeded to compensate for the keystrokes being entered by the user. Inthis event, the keyboard operation may be terminated through the use ofan automatic hardware shutdown procedure. Subsequently, the keyboardoperation will be terminated until the remaining battery capacityreturns to predetermined levels. For example, a remaining batterycapacity of 90% or greater may be considered a High energy reservestatus, whereas a remaining battery capacity of greater than 30% andless than or equal to 80% may be considered a Fair energy reservestatus. A battery state of 0% may be considered critically low ordepleted.

FIG. 10 is a simplified state diagram illustrating operation of thesolar keyboard according to an embodiment of the present invention. Theboxes labeled 1-7 represent power sustainability states. Each box 1-7shows an example of the content that may be displayed in status messagepane 703 when the keyboard is determined to be in the correspondingstate. Arrows labeled {C1, C2, C3 . . . C12} indicate state transitions.In an embodiment, determining the current state depends on the remainingbattery capacity level and light exposure level at the most recentsnapshot in time and trend information over a time interval in additionto the previously determined state. In an alternative embodiment,determining the current state may be performed independent of theprevious state. Regardless of whether previous state is used todetermine current state, the arrows {C2, C3 . . . C12} indicate anexpected sequence of states.

The statuses shown in Table 2 are based on the most recent remainingbattery capacity data point. That is, the energy reserve statusrepresents the present status in the embodiment illustrated in Table 2.The message provided to the user, however, may consider historical data.For example, the message that may be generated when the energy reservestatus is in the Fair state when the battery capacity trend isdecreasing may be:

-   -   Status: Needs more light    -   Your energy reserve is getting low.    -   What should I do?    -   It looks like your keyboard isn't getting enough light. Its        energy reserves are low and getting lower as you use it.        Fortunately, that's easy to fix. Just expose your keyboard to        more light—and make sure it's exposed to light when you're not        using it, too. Note: it will take several days for the status to        be updated.    -   Need help figuring out if it's getting enough light? Press the        CheckLight button on your keyboard and check that the lux gauge        indicates 100 lux or more. If not, try moving your keyboard        closer to a window or light source.

The message generated when the energy reserve status is Fair and thebattery capacity trend is increasing may be:

-   -   Status: Good    -   Your energy reserve is fair but increasing.        In addition, the trend of the light exposure may also affect the        generated message. For example, when the energy reserve status        is Fair, the battery capacity is decreasing, but the light        exposure level is increasing, the message may be:    -   Status: Light has improved    -   Energy reserve is still low however.    -   What should I do?    -   Your keyboard reserve is still low but it appears that the light        intensity it receives has recently increased. However it will        take several days for this to have a measurable effect on the        energy reserve. We will tell you as soon as we detect this. In        the meanwhile, try to keep or even increase this level of light        if possible, even when you are not using your keyboard. Like a        green plant.

Therefore, in some embodiments, the messages can be modified based onthe trend of the keyboard usage and light intensity. Thus, embodimentsof the present invention are not limited to the particular order ofmessage delivery discussed above, but can be modified based on theparticular implementation. One of ordinary skill in the art wouldrecognize many variations, modifications, and alternatives.

Embodiments of the present invention provide feedback through both thepower status indicator unit 120 and/or the power management application700. The power management application enables users to evaluate theirsurroundings and adjust the light exposure level based on their usageand/or the drain on the battery. Thus, embodiments of the presentinvention provide for many different scenarios that provide a user witha solar powered device that is reliable, which is important inimplementations in which the solar keyboard is the user's only inputsource for the user's computer. Thus, embodiments of the presentinvention overcome many of the obstacles previously presented inrelation to solar keyboards.

As will be understood by those of skill in the art, the presentinvention may be embodied in other specific forms without departing fromthe essential characteristics thereof. Accordingly, the foregoingdescription is intended to be illustrative, but not limiting, of thescope of the invention which is set forth in the following claims. It isalso understood that the examples and embodiments described herein arefor illustrative purposes only and that various modifications or changesin light thereof will be suggested to persons skilled in the art and areto be included within the spirit and purview of this application andscope of the appended claims.

What is claimed is:
 1. A method for displaying power sustainability datafor a battery, the method comprising: providing a processor and a memorydevice coupled to the processor; receiving power sustainability data ata plurality of times, the power sustainability data comprising aremaining battery capacity and a light exposure level; storing datavalues in the memory device, the data values associated with the powersustainability data and the plurality of times; obtaining most recentlyreceived data values for remaining battery capacity and light exposurelevel; determining, using the processor, an energy reserve level of theremaining battery capacity; determining, using the processor, a trend ofthe remaining battery capacity characterized as increasing, decreasing,or unchanging; generating a message corresponding to the energy reservelevel and the trend of the remaining battery capacity; displaying, on adisplay device, the message and the most recently received data valuesfor remaining battery capacity and light exposure levels; obtaining aplurality of remaining battery capacity data values and a plurality oflight exposure level data values; and displaying the plurality ofremaining battery capacity data values as a function of time.
 2. Themethod of claim 1 wherein the remaining battery capacity ischaracterized as at least one of high, good, fair, low, very low, ordepleted.
 3. The method of claim 1 further comprising: obtaining aplurality of light exposure level data values and a plurality of lightexposure level data values; and displaying the plurality of lightexposure level data values as a function of time.
 4. The method of claim1 further comprising storing a time of the plurality of times, whereinthe time is associated with the receipt of the power sustainability datastored in association with each data value.
 5. The method of claim 1wherein displaying a most recently received remaining battery capacityis displayed in response to receiving a request to display powersustainability data.
 6. The method of claim 1 wherein displaying a mostrecently received light exposure level is displayed in response toreceiving a request to display power sustainability data.
 7. The methodof claim 1 further comprising displaying the most recently receivedremaining battery capacity in response to receiving an indication fromthe keyboard that the keyboard has been disabled due to critically lowpower sustainability status.
 8. The method of claim 1 wherein the methodfurther comprises: determining an average remaining battery capacityusing a plurality of remaining battery capacity data determined over afirst averaging time interval.
 9. The method of claim 8 wherein themethod further comprises: storing the average remaining battery capacityas the data values in a memory device, wherein the data values arestored in association with a time representing the first averaging timeinterval.
 10. The method of claim 1 wherein the method furthercomprises: determining an average light exposure level using a pluralityof light exposure level data determined over a second averaging timeinterval.
 11. The method of claim 10 further comprising: storing theaverage light exposure level as the data values in a memory device,wherein the data values are stored in association with a timerepresenting the second averaging time interval.
 12. The method of claim1 wherein generating the message further corresponds to the lightexposure level.
 13. The method of claim 1 further comprising:determining that a trend of the light exposure level is increasing,decreasing or unchanging, wherein the message further includes anindicator associated with the trend of the light exposure level.
 14. Themethod of claim 1 wherein determining the energy reserve statuscomprises matching the remaining battery capacity to a particular rangeof a plurality of ranges, wherein the particular range is associatedwith a low threshold value and a high threshold value, and wherein theremaining battery capacity matches the particular range of the pluralityof ranges when the remaining battery capacity is greater than the lowthreshold value and greater than or equal to the high threshold value.15. The method of claim 1 wherein: the processor is coupled to a displaydevice and a keyboard; the power sustainability data is received fromthe keyboard; and displaying the message comprises outputting themessage to the display device.
 16. A non-transitory computer-readablestorage medium comprising a plurality of computer-readable instructionstangibly embodied on the computer-readable storage medium, which, whenexecuted by a data processor, provide a message, the plurality ofinstructions comprising: instructions that cause the data processor toreceive power sustainability data at a plurality of times, the powersustainability data comprising a remaining battery capacity and a lightexposure level; instructions that cause the data processor to store datavalues in the memory device, the data values associated with the powersustainability data and the plurality of times; instructions that causethe data processor to determine, using the processor, an energy reservelevel of the remaining battery capacity; instructions that cause thedata processor to determine, using the processor, a trend of theremaining battery capacity characterized as increasing, decreasing, orunchanging; instructions that cause the data processor to generate amessage using the energy reserve level of the remaining battery capacityand the trend of the remaining battery capacity; and instructions thatcause the data processor to display the message and the most recentlyreceived data values for remaining battery capacity and light exposurelevels, wherein displaying a most recently received light exposure levelis displayed in response to receiving a request to display powersustainability data.
 17. The non-transitory computer-readable storagemedium of claim 16 further comprising: instructions that cause the dataprocessor to determine, using the processor, an energy reserve level ofthe remaining battery capacity characterized as at least one of high,good, fair, low, very low, or depleted.
 18. The non-transitorycomputer-readable storage medium of claim 16 further comprising:instructions that cause the data processor to obtain a plurality ofremaining battery capacity data values and a plurality of light exposurelevel data values; and instructions that cause the data processor todisplay the plurality of remaining battery capacity data values as afunction of time.
 19. The non-transitory computer-readable storagemedium of claim 16 further comprising instructions for storing a time ofthe plurality of times, wherein the time associated with the receipt ofthe power sustainability data stored in association with each datavalue.
 20. The non-transitory computer-readable storage medium of claim16 wherein displaying a most recently received remaining batterycapacity is displayed in response to receiving a request to displaypower sustainability data.
 21. The non-transitory computer-readablestorage medium of claim 16 further comprising instructions that displaythe most recently received remaining battery capacity in response toreceiving an indication from the keyboard that the keyboard has beendisabled due to critically low power sustainability status.
 22. Thenon-transitory computer-readable storage medium of claim 16 furthercomprising instructions that cause the data processor to determine anaverage remaining battery capacity using a plurality of remainingbattery capacity data determined over a first averaging time interval.23. The non-transitory computer-readable storage medium of claim 16further comprising instructions that cause the data processor todetermine an average light exposure level using a plurality of lightexposure level data determined over a second averaging time interval.24. The non-transitory computer-readable storage medium of claim 23further comprising instructions that cause the data processor to storethe average light exposure level as the data values in a memory device,wherein the data values are stored in association with a timerepresenting the second averaging time interval.
 25. The non-transitorycomputer-readable storage medium of claim 16 further comprisinginstructions that cause the data processor to store the averageremaining battery capacity as the data values in a memory device,wherein the data values are stored in association with a timerepresenting the first averaging time interval.
 26. The non-transitorycomputer-readable storage medium of claim 16 wherein the message furtherincludes the light exposure level.
 27. The non-transitorycomputer-readable storage medium of claim 16 further comprisinginstructions that cause the data processor to determine that a trend ofthe light exposure level is increasing, decreasing or unchanging,wherein the message further includes an indicator corresponding to thetrend of the light exposure level.
 28. The non-transitorycomputer-readable storage medium of claim 16 wherein determining theenergy reserve status comprises matching the remaining battery capacityto a particular range of a plurality of ranges, wherein the particularrange is associated with a low threshold value and a high thresholdvalue; and wherein the remaining battery capacity matches the particularrange of the plurality of ranges when the remaining battery capacity isgreater than the low threshold value and greater than or equal to thehigh threshold value.
 29. The non-transitory computer-readable storagemedium of claim 16 wherein: the processor is coupled to a display deviceand a keyboard; the power sustainability data is received from thekeyboard; and displaying the message comprises outputting the message tothe display.
 30. A solar keyboard power management system comprising: asolar keyboard operable to provide character data to a processor device,wherein the solar keyboard comprises: a keystroke input module; abattery; one or more solar panels electrically coupled to the battery; apower sustainability computation module; a power status input device;and a power status indicator unit comprising a first LED and a secondLED, wherein the solar keyboard power management system is operable tocause the first LED or the second LED to illuminate; and a graphicaluser interface operable to provide power sustainability data, thegraphical user interface comprising: a light level indicator pane; abattery information pane; and a status message pane.
 31. The solarkeyboard power management system of claim 30 wherein the power statusinput device comprises a button.
 32. The solar keyboard power managementsystem of claim 30 wherein the power sustainability computation moduleis enabled to determine a power sustainability status displayable in thestatus message pane and the power status indicator unit.
 33. The solarkeyboard power management system of claim 30 further comprising anon/off switch operable to transition from a first position to a secondposition.
 34. The solar keyboard power management system of claim 30wherein the light level indicator pane comprises a numerical rangeindicator and a digital readout associated with a light intensity level.35. The solar keyboard power management system of claim 30 wherein thebattery information pane is operable to display a remaining batterycapacity or a plot of the remaining battery capacity as a function oftime.